This introduction presents the central concepts, principles, and methods of psychosynthesis within the context of a modern methodological guide. Ursel Neef, the founder of the Wuppertal Institute for Psychosynthesis and Interpersonal Psychology, summarizes her 25 years of work as a therapist and teacher with the systematically integrative psychosynthesis (SIPS) she developed. Georg Henkel, who became a lecturer at the institute after his SIPS training, explores, among other things, the structure that Roberto Assagioli based his work with patients on from various perspectives.